Information

Diabetes Mellitus in Dogs


Overview
Diabetes mellitus is a common condition in people and relatively common in dogs, as well. It is a chronic condition in which the body either isn’t making enough insulin or isn’t responding to the insulin being produced. Insulin, a hormone secreted by the pancreas, helps regulate blood sugar (glucose). Glucose is a by-product of the food our dogs eat; it provides energy to the cells in their bodies.

There are two common types of diabetes mellitus. The first type occurs when your dog’s body can’t produce enough insulin; this is called type 1 diabetes. The second type of diabetes occurs when the body doesn’t respond to insulin; this is called type 2 diabetes. Dogs almost exclusively have type 1 diabetes. Occasionally, diabetes can be secondary to underlying disease, such as severe pancreatitis.

Risk
Diabetes usually affects middle-aged to older dogs, and those who are overweight are also at higher risk. While both male and female dogs can become diabetic, it is much more common in females. Some breeds are at a higher risk as well.

These include:

  • Samoyed
  • Beagle
  • Bichon frise
  • Australian terrier
  • Schnauzer
  • Cairn terrier
  • Keeshond
  • Poodle
  • Fox terrier

The breeds that are at higher risk of diabetes in the UK are:

  • Larador Retrievers
  • Collies
  • Cair Terriers
  • Poodles

Signs
The most common symptoms of diabetes are increased thirst (polydipsia) and increased urination (polyuria).

Other symptoms include:

  • Hunger
  • Weight loss (despite a normal appetite)
  • Lethargy
  • Depression
  • Vomiting
  • Vision loss

Diagnosis
Your veterinarian will perform a thorough physical exam and take a detailed history of your pet’s health. The symptoms of diabetes mellitus are very similar to other diseases, such as Cushing’s syndrome, liver or kidney disease, Addison’s disease, and hypothyroidism. Sometimes, underlying diseases or conditions can cause interim diabetes, and once the primary disease or condition is treated, the diabetes resolves.

Your veterinarian may recommend diagnostic tests to identify the underlying cause of your pet’s symptoms. These could include:

  • Chemistry tests to evaluate kidney, liver, and pancreatic function, as well as sugar levels
  • A complete blood count (CBC) to rule out blood-related conditions
  • Pancreas-specific testing to screen for underlying or concurrent pancreatitis
  • Electrolyte tests to ensure your pet isn’t dehydrated or suffering from an electrolyte imbalance
  • Urine tests to screen for urinary tract infection and other disease, and to evaluate the ability of the kidneys to concentrate urine
  • A thyroid test to determine if the thyroid gland is producing too little thyroid hormone
  • An ECG to screen for an abnormal heart rhythm, which may indicate underlying heart disease
  • Abdominal ultrasound to evaluate the major abdominal organs, including the pancreas
  • Cortisol tests to evaluate your dog’s blood-cortisol levels

Treatment
The treatment of diabetes mellitus almost always involves once- or twice-daily injections of insulin to help regulate your dog’s blood glucose level. Here are two videos, caring for your diabetic dog and giving injections to your pet, which may be useful to you.

If you have any questions or concerns, you should always visit or call your veterinarian – they are your best resource to ensure the health and well-being of your pets.


It’s an effort

Caring for a dog with diabetes can be time-consuming, expensive, and stressful. In fact, the initial diagnosis can be overwhelming.

According to Dr. Bruyette, “Several studies have shown that euthanasia is a common cause of death in diabetic dogs and cats mainly as a result of the owners’ concerns, real or perceived, regarding the care of pets with diabetes. It is very important that we emphasize to pet owners that while diabetes is a chronic disease, it can be well controlled with minimal disruption of their lives while maintaining their pet’s quality of life.”

Sheila Laing of Lansing, Michigan, cared for her Lab/Shepherd mix, Zachary (pictured at top), for four years after he was diagnosed with diabetes at age 11. “Zachy was my soul mate and my teacher,” she says. “I am so lucky that I was able to help him lead a healthy normal life in his senior years in spite of the diabetes. People need to know that diabetes doesn't have to be a death sentence. It can be managed!”

Coming next month: Diabetic diets in action menu planning and canine diabetes success stories.

Hazards of hypoglycemia (low blood sugar)

Hypoglycemia is a serious risk factor in diabetes management. Recent studies suggest that approximately 10 percent of diabetic dogs experienced hypoglycemic episodes that required hospitalization. One large survey found that the majority of diabetic dogs presented for hypoglycemia were receiving high doses of insulin (0.7 units or more per pound of body weight).

Overdosing, double-dosing, and persistent dosing despite weight loss or reduced food intake are common iatrogenic causes of hypoglycemia. (Iatrogenic diseases are caused by medical treatment.) Strenuous exercise or maldigestion caused by EPI, bacterial overgrowth, inflammatory bowel disease, or other digestive disorders can also lead to hypoglycemia in diabetic dogs.

If you’re ever uncertain about whether insulin was administered, the safest option is to withhold the injection. The consequences of missing a single insulin dose are negligible, while overdosing can be fatal. Never add more if you are unsure, including if some insulin spills while you give the injection.

Changes in body weight may require insulin dosage modifications. Dietary changes, particularly reduced carbohydrates, may require a reduced insulin dosage to prevent hypoglycemia.

Severe hypoglycemia resulting from too much insulin can cause seizures, irreversible brain damage, and death. Warning signs include nervousness, hyperexcitability, anxiety, vocalization, muscle tremors, lack of coordination, wobbliness (the dog may appear drunk), and pupil dilation.

If these signs are seen, the dog should be fed immediately. If the dog can’t or won’t eat, rub Karo syrup, pancake syrup, honey, or even sugar water on her gums before calling your veterinarian. If your dog responds, feed a small, high-protein meal and keep your dog as quiet as possible. If immediate improvement is not seen, transport your dog to the vet after feeding for further care, such as intravenous glucose. Don’t give any more insulin until you have consulted with your vet, as insulin may need to be reduced for a few days, or long term.

When your pet’s condition stabilizes after a hypoglycemic episode, a glucose curve can help to determine why this happened and what a more appropriate insulin dose might be. A glucose curve is a series of blood sugar measurements made after insulin is given. Typically, blood samples are taken every 1-1/2 to 2 hours for 10 hours, or until the effects of the insulin injection can be determined. For ease of understanding, measurements are plotted on a graph whose points usually form a curve. Glucose levels can be monitored at home, improving the accuracy of the data.

Cerebral edema caused by insulin overdose can result in temporary blindness or behavior changes. These signs often resolve over several weeks or months.

If a concurrent illness causes prolonged loss of appetite, the patient should be hospitalized for blood glucose concentration monitoring and treatment with rapid-acting insulin and intravenous fluids supplemented with glucose and potassium.

Update: A study published in 2012 indicates that administering glucagon subcutaneously may be effective in treating hypoglycemia due to too much insulin. Human emergency glucagon kits are available that may be useful for those with diabetic dogs. See Using a Glucagon Emergency Kit for Insulin-Induced Hypoglycemia for more information.

Resources

Glycemic index:

Fiber content in various foods (keep in mind that portion sizes vary):

  • Fiber Content in Foods Includes a breakout of soluble and insoluble fiber
  • Carbohydrates 2: Dietary Fibers
  • Fiber Content of Foods in Common Portions
  • Fiber (also lists soluble and insoluble fiber content of various foods)
  • You can also find the amount of soluble and insoluble fiber in at least some foods in the In-Depth Nutrient Analyses provided on the World's Healthiest Foods website. You must first search for the food, then select the entry under "Foods and Spices," then scroll to the bottom of the page and select "In-Depth Nutritional Profile" (below the limited nutrient table, just above References).

Instructions for giving insulin injections:

VCA West Los Angeles Animal Hospital, 1818 S. Sepulveda Blvd., Los Angeles, CA 90025, (310) 473-2951. David Bruyette, DVM, DACVIM.

Support Groups

References

Encyclopedia of Canine Clinical Nutrition: Diabetes Mellitus
Linda Fleeman BVSc MACVSc and Jacquie Rand BVSc DVSc Dipl ACVIM, 2008

Kirk’s Current Veterinary Therapy XIV
John D. Bonagura DVM MS Dipl ACVIM,В David C. Twedt DVM DipACVIM,В 2009.

Small Animal Clinical Nutrition
4th Edition, Michael S. Hand,В Craig D. Thatcher,В Rebecca L. Remillard,В Philip Roudebush,В Lon D. Lewis, 2000.

Blog posts by Dr. Mark E. Peterson, veterinary endocrinologist:

Insulin Choices:

I regret that I no longer have much time to respond to questions. See my Contact page for more information. My name is Mary Straus and you can email me at either or


Causes

The presence of diseases such as diabetes, hyperadrenocorticism or kidney disease may cause incontinence, according to the American Society for the Prevention of Cruelty to Animals (ASPCA). A diabetic dog's pancreas doesn't produce the correct level of insulin, causing his blood sugars to fluctuate. When the dog's blood sugars rise, his kidneys signal the need for increased urination. Since elevated levels of blood sugars are toxic to many organs, the dog's kidneys try to rid themselves of the poison, according to the Doctors Foster and Smith Pet Education website. This cycle can lead to involuntary urination, also known as incontinent behavior.


Feline Diabetes: Symptoms, Treatments, Prevention, and Diet Tips

Thomas Graves and WebMD team up to provide feline diabetes information and tips for treatment or prevention.

An alarming number of cats are developing diabetes mellitus, which is the inability to produce enough insulin to balance blood sugar, or glucose, levels . Left untreated, it can lead to weight loss, loss of appetite, vomiting , dehydration , severe depression, problems with motor function, coma, and even death. To find out why so many cats are being diagnosed with diabetes, and what owners can do, WebMD talked to Thomas Graves, a former feline practitioner who is associate professor and section head of small animal medicine at the University of Illinois College of Veterinary Medicine. Graves’ research focus is on diabetes and geriatric medicine.

Q: How common is feline diabetes?

A: The true incidence isn’t known, but it’s estimated at 0.5% to 2% of the feline population. But it’s also probably under diagnosed.

Q: What are the signs of diabetes in cats?

A: The main symptoms are increased thirst and increased urination. And while we do see it in cats with appropriate body weight, it’s more common in obese cats. Some cats with diabetes have a ravenous appetite because their bodies cannot use the fuel supplied in their diet.

Q: What’s the treatment for a cat with feline diabetes?

A: Diet is certainly a component. It’s felt that a low-carbohydrate diet is probably best for cats with diabetes. Treatment is insulin therapy. There are some oral medications, but they have more side effects and are mainly used when insulin can’t be used for some reason. There are blood and urine tests, physical examinations, and behavioral signals, which are used to establish insulin therapy. This is done in conjunction with your veterinarian. We don’t recommend owners adjust insulin therapy on their own because it can be sort of complicated in cats. Most patients come in every three or four months. It’s a good thing to make sure nothing else is going on.

Q: Will I have to test my cat’s blood every day and give them shots?

A: Usually the blood tests are done during the regular visits with your veterinarian, although people can do them if they’d like. But the owners will have to give their cat shots. People are often afraid of that whole thing. But once you teach an owner how to do it properly, it’s something people find quite easy. Many people even find it a bit empowering, that they can do something like that to help their pet.

Continued

Q: If caught early enough, can my cat be cured of diabetes?

A: It’s usually not cured. Some cats, when you start treating their diabetes and you get their blood sugar under control and get them on a reasonable diet and get them in a better body condition, their diabetes actually goes into remission or partial remission. There are cats that stay that way for many months. Some might even stay that way for years. It can happen. But for the most part diabetes is a disease that we control and don’t really cure.

Q: Can I prevent my cat from getting diabetes with diet and not letting them get too fat?

A: Nobody can tell you that you can prevent your cat from getting diabetes with diet because those studies haven’t been done. There are some commonly held beliefs, based on a handful of clinical studies, that support the use of low-carbohydrate diets in helping diabetic cats control their blood sugar better. And we do know that obesity is a risk factor. But there also are some breeds of cats that get diabetes more than others do, so that suggests there may be a genetic component involved as well.

Q: Will it be better for my cat if I cook instead of buying them food?

A: It’s hard to make a decent, balanced diet for a cat if you’re cooking it. You have to make sure they get all the amino acids that they need, and their needs are different from dogs and people and other omnivores. You have to know what you’re doing.

Q: Should I only feed them dry food or just wet food or both?

A: That’s the raging argument right now. It’s fairly controversial. If you think about what a cat’s natural diet would be, they’re carnivores. So the diet they would eat, if they were running around outside eating the animals that they prey upon, would be a very high-protein, very low-carbohydrate diet. So the argument is, that is what they have evolved to eat and that is healthier for them. So why do we have dry food for cats ? Because it’s more convenient for people. Some people just don’t like dealing with canned food. And there are a gazillion cats that eat dry food and don’t get diabetes. We see 20-year-old cats that eat dry food.

Continued

Q: Will diabetes shorten my cat’s lifespan?

A: It sure can, because it can be associated with infections, with peripheral nerve disorders, and other problems. If it’s poorly controlled you can get into some pretty severe emergency situations. But I can tell you that we see lots of diabetic cats that are older that are managed for many years and they can get into their late teens. It requires a lifelong, daily commitment, but it’s something that can be done.

Q: What does it cost to care for a diabetic cat?

A: Most clients probably spend about $20-$30 a month on insulin, syringes, and other supplies. It’s not terribly expensive once it’s being managed.

Q: What are the newest treatments for feline diabetes?

A: There are newer insulins that are being evaluated. Some of the insulin analogs that are available for treating human diabetics are being looked at in diabetic cats and they have some promise. These provide more blood sugar control, often with fewer side effects. People are constantly trying to find new and better ways to care for diabetic cats.


CATARACTS IN THE DIABETIC DOG

Most diabetic dogs will develop cataracts and go blind. This web page is arranged as an FAQ to assist the owners of diabetic dogs in knowing what to expect and in decision-making regarding cataract surgery.

WHAT IS A CATARACT?

A cataract is an opacity in the lens of the eye. The entire lens may be involved or just a part of it. The patient will not be able to see through the opacity.


(Photocredit: Public Domain Graphic via Wikimedia Commons)

WHY DO DIABETIC DOGS GET CATARACTS?

The lens of the eye is round, hard, and normally as clear as glass. Looking at the lens it is hard to believe it is a piece of living tissue. The lens is suspended by fibers which can adjust its position so that one can focus. The lens is encased in a capsule and depends on the fluids of the eye for nutrients. The lens does not receive a direct blood supply.

Normally, the lens absorbs glucose from the eye fluids, using most of this for its own energy needs. Some of the excess is converted to another sugar called “sorbitol.” When there is excess sugar in the eye fluids, there is excess sorbitol produced. Sorbitol pulls water into the lens which in turn disrupts lens clarity and causes the cataract. Fructose is also produced from the excess glucose and also contributes to this water imbibition.


(Photocredit: Public Domain Graphic via Wikimedia Commons)

The presence of cataracts does not necessarily imply poor diabetic control. Even well controlled dogs still can get cataracts.

HOW LONG DOES IT TAKE TO GO BLIND?

Generally the cataract has matured and the dog is blind in a matter of weeks.

Until recently, the development of blindness in a diabetic dog was basically a foregone conclusion but there is a new product called Kinostat® which has changed this. To review, the lens absorbs glucose from the fluids of the eye and uses this glucose as nutrition. Any extra glucose that is absorbed into the lens is converted to sorbitol by an enzyme called aldose reductase. Sorbitol pulls water into the lens to prevent the lens from becoming dehydrated. This is all well and good but in the diabetic state there is lots of excess glucose and the excess glucose gets converted to excess sorbitol which, in turn, pulls so much water into the lens that clarity and function are disrupted and a cataract is formed. Kinostat is an aldose reductase inhibitor which curtails the production of sorbitol. Early use of Kinostat may significantly delay or even completely prevent the development of cataracts.

Kinostat is a preventive only and will not reverse cataract formation that has already occurred.

WHAT DOES IT MEAN TO SAY THAT A CATARACT IS “MATURE?”

A cataract’s “maturity” is determined by how much visual impairment is felt to be present. Since we cannot ask a dog to read an eye chart, we must determine this by visual inspection of the eye. A light is used to look into the eye and view the colorful area at the back of the eye called the “tapetum.” (This is the area that flashes or appears colored in certain lighting.) When less than 10% of the tapetum is obstructed is very young and does not significantly change vision. When 10-50% of the tapetum is obstructed this cataract is called “early immature.” When 51-99% is obstructed the cataract is “late immature.” The “mature” cataract obstructs the entire tapetum. Ideally a cataract is removed in the “early immature” stage for the lowest surgical complication rate.

When a cataract is “hypermature,” it is starting to actually liquefy and dissolve. While this can actually lead to the restoration of vision which sounds like a positive turn of events but the dissolution process is quite inflammatory.

All cataracts do not progress all the way to hypermature and may stay static or progress at changing rates however, diabetic cataracts are notorious for reaching hypermaturity and creating inflammation.

WHAT IS “UVEITIS?”

Uveitis is inflammation of the “uveal tract” of the eye, which consists of the vascular tissues of the eye. In this situation, uveitis is the inflammation that results when the hypermature cataract begins to liquefy. Uveitis is painful and tends to cause the eye to become reddened and the pupil to constrict. When uveitis is present prior to surgery, success (pain-free vision) is present in only 50% of cases 6 months after surgery as opposed to 95% of cases for whom there was no uveitis preoperatively.

CAN MY DOG'S VISION BE RESTORED?

The answer is "maybe." It depends on the health of the eye excluding the cataract. If the only thing wrong with the eye is the cataract and the patient's diabetes mellitus is well regulated, surgery can be performed to remove the cataract and place an artificial lens. If the eye is deeply inflamed or is otherwise damaged, the eye may be blind even without the cataract present. A board certified veterinary ophthalmologist will need to evaluate the eye to determine the feasibility of cataract surgery.

It is important to note that there are numerous eye drops advertised that claim to dissolve cataracts. None of these products actually work and wasting time with them may actually allow for uveitis to set in and make for a much worse prognosis for vision.

IS IT CRUEL TO KEEP A BLIND DOG?

Not at all. Dogs do not depend on vision the way humans do. A blind dog can get a long very well as long as the furniture isn’t moved and the dog is properly supervised.

For tips on helping the blind dog adapt:

There are many medical conditions that render a dog blind and as long as the condition is not painful, the dog can live a normal life as a successful and happy pet.

REGARDING CATARACT SURGERY, WHAT IS THE FIRST STEP?

The first step is a consultation with your regular veterinarian. Your dog’s diabetes must be well regulated before surgery is considered. If pre-operative lab tests show nothing to preclude anesthesia, the next step is referral to a veterinary ophthalmologist. Your regular veterinarian can do this or you may search on your own at

(Web site of the American College of Veterinary Ophthalmologists).
A regular veterinarian is not qualified to perform cataract surgery.

WHAT HAPPENS WITH THE OPHTHALMOLOGIST?

It is necessary to determine if the eye is going to be visual after cataract surgery. There is, after all, no point to performing this surgery if the eye is going to be blind anyway. The most important test is called an “ERG” (an electroretinogram). This test checks the retina for electrical activity which, if present, indicates the eye should be able to see after the cataract in front of it is removed.

In addition to performing the ERG, the ophthalmologist will be checking for uveitis. Uveitis should be treated prior to surgery to minimize the inflammation that is inevitable after surgery.

WHAT KIND OF SURGICAL PROCEDURES ARE DONE?

There are two types of surgery: lens extraction and phacoemulsification. With lens extraction, the incision tends to be larger, the post-operative inflammation is greater, and the potential for leaving bits of lens behind is also greater.

With phacoemulsification an ultrasonic instrument is used to liquefy the lens and a special vacuum cleaner is used to suck the lens away. This procedure is more difficult if the patient is older (and the lens is thus harder in consistency). This is the preferred method for diabetic patients.

Human eye receiving phacoemulsification.

After either surgery an artificial lens is usually placed for optimal post-operative vision.

WHAT KIND OF AFTER CARE IS NEEDED?

The patient will need to wear an Elizabethan collar after surgery to protect the eye. Cortisone eye drops are needed for probably several weeks. Oral anti-inflammatories will be needed for weeks to months after. Drops to keep the pupil dilated will also be used.

WHAT KIND OF COMPLICATIONS ARE POSSIBLE?

Complications to consider are:

  • Long term uveitis (probably of most concern for diabetic patients)
  • Opacification of the lens capsule (usually correctable with laser)
  • Corneal clouding (can be managed with 5% saline eye drops 4-6 times daily)
  • Bleeding into the eye
  • Glaucoma
  • Retinal detachment (particularly if the cataract is hypermature)

SHOULD BOTH EYES HAVE SURGERY?

It is important to remember the old saying that the one-eyed man is king among the blind. A dog need only have one cataract removed to have vision restored. Doing both eyes is an option to discuss with the ophthalmologist as some dogs need all the vision they can get.

Cataract surgery requires committed patient care both in the hospital and at home. Surgery also requires a financial commitment (which varies regionally and between different practices) your regular veterinarian can get a sense for average costs in your community when you are ready to consider restoration of your dog’s vision.


Watch the video: CANINE DIABETES MELLITUS (May 2021).